1) Given a function of state, V, John wants to also call the exact
differential dV a function of state.
As far as I can see, this is just harmless terminology - though confusing
to me. However, I have two notational problems with John's usage:
| Anything you could legitimately do previously (considering
| d(V) as a small variation in V) you can do still (considering
| d(V) as the exterior derivative of V).
(A) Why do you insist on d(V) and not just dV - what is the distinction?
(B) Have you blurred the distinction between a differential and a
derivative? Is not dV a differential and not a derivative (consider its
units!)? A derivative is a RATE of change.
2) The second issue shows in John's wish to obliterate inexact
differentials:
|Bridgman _knew_ there
| was something fishy about d(W) but he couldn't explain it.
You insult Bridgman! He well understood and explicitly explained the
difference between exact and inexact differentials, even acknowledging the
need for different notations ( hence: dE vs dbarQ). dbarQ simply
represents an infinitesimal AMOUNT of energy in the form of "heat".
No-one pretends that it is the differential of a function. Are we
forbidden to use a symbol for such a quantity?